It is known to inhibit blood platelet aggregation by administering compounds having a pyrazine ring as a main nucleus. Thus, tetramethyl pyrazine has been proposed for this purpose [Abstract of the 16th Congress of Heterocyclic Chemistry (Osaka), pp. 65-68 (1984)], as have also 2-higher fatty acyloxymethyl pyrazines (Japanese Unexam. Publ. KOKAI No. 59-219269).
On the other hand, 2-hydroxy-3-isopropyl-5,6-dimethylpyrazine is a known compound which has been synthesized by Reuben G. Jones [J. Am. Chem. Soc., 71: 78-81 (1949)]. However, the pharmacological activity thereof was unknown.